Thanks to Richard Overthrow for putting me onto this. I’ve always said that there is more value to allotments than appears on the surface. Usually I’ve talked about social and health benefits and I have even been known to mention food miles but one thing I’ve not really thought about is the quality or health of the soil.
Modern agriculture is efficient in terms of crops produced per man hour because it uses a lot of machinery. Giant tractors that can pull huge loads are all well and good but they compact the soil with their weight.
High use of artificial fertilisers push plant growth but do nothing positive, and lots of negative, to the eco-system of the soil. Those bacteria and microscopic organisms that work together with the plants are reduced in number. Imagine the soil as a person on a diet of fast foods, filled up on pizza and burgers with no room left for the 5-a-day vegetables.
Finally, modern agricultural practice may distribute some animal manure (most often as slurry) back onto the land but there’s no compost making program. So precious little humus, organic matter, in the soil.
Humus is a bit like fibre in the diet. It doesn’t add nutrients as such but it keeps the system open and working. Humus in the soil holds water during drought and absorbs it during flood.
Sustainable Production depends on Soil Quality
In a period of rising food demand, it’s self evident that sustainable production will maintain the quality of the soil or better still, improve it to maximise its production potential.
This is where allotments come in – an increase in urban allotments could help us meet the rising demand for food throughout the world, without damaging the Earth’s soils, according to new research from the University of Sheffield.
Dr Jill Edmondson from the University’s Department of Animal and Plant Sciences, has found that soils under Britain’s allotments are significantly healthier than soils that have been intensively farmed.
Ecologist Dr Edmondson took soil samples from 27 plots on 15 allotment sites from across the city of Leicester. She also sampled soils from local parks, gardens and surrounding agricultural land and used these to measure a range of soil properties, including soil organic carbon levels, total nitrogen, and the ratio between carbon and nitrogen (which are all directly related to the amount and quality of organic matter in the soil) as well as soil bulk density, an indicator of soil compaction.
Allotment soil found to be significantly healthier.
The results won’t surprise allotment holders and home veg growers. Compared with local arable fields, the allotment soil was found to be significantly healthier. Allotment soil had 32 per cent more organic carbon, 36 per cent higher carbon to nitrogen ratios, 25 per cent higher nitrogen and was significantly less compacted.
Dr Edmondson, said:
“We found remarkable differences in soil quality between allotments and arable fields. Our study shows how effectively own-growers manage soils, and it demonstrates how much modern agricultural practices damage soils.”
Allotment holders are able to produce good food yields without sacrificing soil quality because they use sustainable management techniques. For example, 95 per cent of allotment holders compost their allotment waste, so they recycle nutrients and carbon back to their soil more effectively.
Dr Edmondson also said
“An estimated 800 million city dwellers across the world participate in urban food production, which makes a vital contribution to food security. Our results suggest that in order to protect our soils, planning and policy making should promote urban own-growing rather than further intensification of conventional agriculture as a more sustainable way of meeting increasing food demand.”
When you consider that during WW2 10% of Britain’s home food production came from the 1% of the land which was the allotments and gardens turned to food production in the ‘Dig for Victory’ campaign, her views make a lot of sense.
Hopefully our government can see beyond the next election to the future when Britain will need to feed its population in a situation of rising costs and reducing availability of food and hang onto allotments. Because even if they’re not fully utilised today, in 20 years time we’re likely to need every square inch of land.
Dr Edmondson’s study “Urban cultivation in allotments maintains soil qualities adversely affected by conventional agriculture” has been published in the Journal of Applied Ecology.
Well !!!! AS a farmer and a very keen gardener I see both sides of this …… and there is a lot I disagree with but one thing I will add may give people food for thought ….
allotments have 25 higher nitrogen …….. now modern farming has to deal with MASSES of red tape. Are you all familiar with the term NVZ ‘s ? Nitrate Vulnerable Zones. So a framer has restrictions on what and how much manure / artificial fertiliser is applied in any season and when.
Farming has had to clean itself up in the last decade or so.I’m 41yrs old and in my life time nitrogen has gone from £75 / ton to £325 / ton in recent years, so any farmer is only going to apply what the plant needs to take it through the growing period and not have excess to run into the rivers
The machinery has got bigger, 200hp tractors were extremely rare 10 yrs ago but now any big contractor/farmer will have one or two. My eyes water at just how much fuel they burn but it gets pointed out to me that they can achieve less fuel use per acre that I can with my 100hp and the smaller machines.
And as more and more tractors and combines get fitted with ever bigger tyres or even tracks, probably the biggest contribution to compaction is the ontop cultivation. Not a traditionalists friend but I have to admit to its uses .
Now the organic mater: With the ever decreasing amount of livestock in the country is it any wonder that this figure is lower?
I will leave this for you all to ponder. If there was no Asda / Tesco / Morrison etc. what would things be like? They have driven the prices down for you but in turn paid less to us, so you have to look at cheaper ways to produce. Farms have got bigger and bigger in order to produce cheaper and cheaper food. More uniform shaped veg – its all about shape and looks on the shelf. Taste is never a thought. Do you worry about the shape from your garden / allotment. When I’m looking for seeds / sets I think what was around when I was 16 and try to find those varieties. They yield much the same but maybe not the shape but the taste !!!
@Allan: That’s a really interesting comment. You make some good points. For me the most telling is how the retail supermarket cabal has forced farming down this cheap food road.
Ultimately the ‘blame’ lies with us for our shopping patterns. Ask people if they want organically and sustainably produced food, cruelty free meat and 99% say yes. Ask them if they’re willing to pay extra for that and the answer is very different.
well if you think back 15 – 20 years …. how many butchers/fruiters/bakes were on the high streets teamed with other traders ….
so now look at our high streets .
Today it difficult to blame ….realy anyone is going to go where its cheapest ….thats not the shopper fault …but as buisnesse get bigger and they float on the stock exchange ….what is more important then …. profit / footfall and market share …. so who is the winner then ….. its not you or us thats for sure .
The best food is out of my garden ….. I will never eat a shop bought tomato … only from my greenhouse …. they a already flowering 🙂 yipee …
By way of comment. Scientific data shows us that High yielding crops have high above ground biomass as well as high below ground biomass – lots of roots! the latest research (Andy Whitmore Rothamsted Research) is suggesting that this fact also then means that a very high soil fauna is supported giving greater biodiversity. If we accept that we are not prepared to limit population growth, then maths tells us that the amount of reactive nutrient (N & P especially) in our living world will increase whether from organic systems or fertilizer so it then comes down to maximizing efficiencies via matching crop uptake with nutrient supply and avoiding leakage – so a useful comparison might be how leaky are systems. Highly organic soils which readily mineralise nitrogen can be leaky if the N released is not trapped. This is why modern farming uses cover crops / catch crops to trap nutrients as well as improving soil health. It will all come down to economics – it drives everything unfortunately.